1. Field of the Invention
The present invention relates to a module for integration into a mobile terminal, in order to estimate the temperature of the surroundings of the mobile terminal.
2. Description of the Related Art
The temperature of the surroundings of a mobile terminal may only be determined with limited accuracy, using a temperature sensor situated on the mobile terminal, since the specific heat and/or the self-heating and the thermal inertia of the mobile terminal falsifies the direct measurement of the ambient temperature. A method, according to which the temperature difference between two temperature sensors situated at different locations within the mobile terminal, is used for estimating the temperature of the surroundings of the mobile terminal, is known from published European patent application document EP 1 301 014 A1. In this context, as a rule, the temperature sensors measure different temperatures, since further components or assemblies of the mobile terminals form heat sources through their operation, which cause the temperature to change over the extension of the mobile terminal. In addition, the various components have different heat capacities, which produce different response rates; and they are thermally linked to the environment to different extents, which produces different final temperatures. For example, as a rule, a temperature sensor situated in the interior of the mobile terminal will have a higher temperature than a temperature sensor that is situated on a housing of a mobile terminal. The ambient temperature may then be estimated in light of the temperature difference between the two temperature sensors. In this context, a requirement for accurately estimating the ambient temperature is careful calibration, that is, modeling the thermal behavior of the entire mobile terminal. Since, as a rule, the temperature sensors are mounted at different locations in the mobile terminal, one would have to provide careful calibration of each individual device, specific to device type, in a costly and time-consuming manner. Therefore, considering the number of different types of devices, the calibration is expensive and time-consuming.
The object of the present invention is to provide a device, by which the temperature of the surroundings of a mobile terminal may be ascertained in as accurate a manner as possible, and in which the expenditure for calibration is simultaneously limited.